CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parentheticals) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2012
Statement of Stockholders' Equity [Abstract]
Income tax (expense) benefit related to changes in unrecognized pension benefit costs	$ (63)	$ (785)	$ 1,260
Income tax benefit related to foreign currency translation adjustments	$ 3,133	$ 582	$ 6,879
Dividends per share (in dollars per share)	$ 0.08	$ 0.08	$ 0.08